The present disclosure relates to an electropneumatic solenoid valve or magnet valve for a pneumatically actuated field device (e.g., a positioner), such as a position controller, of a processing plant, such as a chemical plant, a petrochemical plant, a food processing plant (e.g., a brewery), a power plant (e.g., nuclear, coal, natural gas, etc.) or the like.
A generic electropneumatic magnet valve has a housing structure in which usually an air supply channel for connection to a source of pressurized air, an air dispensing channel, and an air exhaust channel are formed. A flapper valve member, such as a flapper plate, is movably mounted within an air chamber. An electropneumatic control device positions or displaces the flapper valve member between two operation positions, in which one of the air canals, respectively, is closed. The flapper valve member is can be moved in an axial control direction. Furthermore, the magnet valve includes a biasing means, such as a spring, which urges the flapper valve member in the axial control direction into a closed position for closing one of the air channels. The flapper valve member has a magnetic flapper plate which is float-mounted inside the air chamber guiding-free except for the biasing means.
An example electropneumatic magnet valve having a flapper plate as a flapper valve member is described in German Patent document DE 196 36 207 C2. The magnet valve requires a precise manufacturing, and more so when a precise closure of the respective air channel shall be achieved with low energy consumption.
The exemplary embodiments of the present disclosure will be described with reference to the accompanying drawings.